Data mining involves the processing and extraction of patterns from data. Observations about form, behavior, or the nature of concepts represented by data can be used to create useful intelligence about the concepts. Many data mining processes are computationally complex, and are often performed by computer systems with access to a large collection of data (e.g., web documents or other electronic documents). Documents or other data that meet particular criteria may be referred to as a corpus, and data mining operations may be performed on the corpus to create intelligence about the corpus or about documents or other data items within the corpus. For example, structured attributes for a web document that provides information about a particular place can be analyzed to identify keywords or categories associated with the web document and/or the place. Other documents within the corpus can also be analyzed to similarly identify keywords or categories.